Create a lock button in Windows 8

Go to the desktop, right click a blank area and select new-> shortcuts
then type rundll32.exe user32.dll,LockWorkStation in the type the location of the item box
click next, then give a name to the shortcut, say Lock, in the type a name for this shortcut box
the default shortcut icon doesn't look the part so it is nicer to change it to something better.
So right click on the newly created shortcut icon and then select properties
click change icon, browse to windows\system32\shell32.dll to the list of windows icons that you can use.
after selecting the icon you want, click ok and then apply
Now you can right click the created shortcut icon and select pin to taskbar for easy access to lock your computer.
Thats it